Oystermouth Castle

A number of Antiquarians state that the Norman castle was built on the site of a former native fortification. Nineteenth century works by Samuel Lewis and Nicholas Carlisle both name this fortification as the "Caer Tawy" of Medieval Welsh literature. The name indicates that a Welsh fort (a Caer) was built here to guard the river Tawe long before Oystermouth or Swansea Castle were built by the Normans.

The first Norman castle was founded by William de Londres of Ogmore Castle soon after 1106 following the capture of Gower by the Normans. In 1116 the Welsh of Deheubarth retook the Gower Peninsula and forced William to flee his castle which was put to the torch. The castle was rebuilt soon afterwards, but was probably destroyed again in 1137 when Gower was once more retaken by the Princes of Deheubarth. The Londres or London family finally died out in 1215 when Gower was again taken by the Welsh under the leadership of Llywelyn the Great.

After the Middle Ages, the castle gradually fell into ruin. A survey of Gower made in 1650 describes Oystermouth Castle as [a]n old decayed castle of no use, but of a very pleasant situation. It was portrayed in art in the 18th century as a picturesque ruin, and was restored by George Grant Francis in the 1840s while the castle was owned by the then Duke of Beaufort.